Sprocket



FIG. 1 is a front perspective view.

FIG. 2 is a front elevation view.

FIG. 3 is a side elevation view.

FIG. 4 is a top plan view; and,

FIG. 5 is a rear elevation view.

The broken lines shown on the sprocket are included for the purpose of illustrating portions of the sprocket which form no part of the claimed design. 

CLAIM The ornamental design for a sprocket, as shown and described. 